The gene encoding for cytosolic Phospholipase A/2 has been cloned. Work is now progressing on determining the sequence of the 5' promoter region of the gene. The sequence will help to understand the mechanism of control of gene expression of this important enzyme. A genomic library has been probed with probes utilizing the known 5' untranslated sequence of the gene. Two clones have been isolated and partially sequenced. A 5.7kB clone containing a portion of the first intron, the first exon and about 600 bases above the 5' untranslated region was subcloned and the 5' promoter region sequenced. The transcription start site was determined. Reporter genes containing sequences of up to 595 bases of the 5' promoter region were constructed and transfected into a respiratory epithelial cell line. The constructs demonstrate functional promoter activity. A second clone contains an additional 700 bases of 5' sequence and is currently being sequenced and utilized for a larger reporter gene construct. This project will allow for some insight into the control of gene expression of this important enzyme.